Daniel O'Sullivan (born 1 December 1980) is an English musician and composer from Manchester, best known for playing in experimental art-rock bands Grumbling Fur, Guapo, Miasma & the Carousel of Headless Horses, Ulver, Sunn O))), Æthenor, Laniakea, Miracle, Mothlite, and This Is Not This Heat.

O'Sullivan is recognised for exploring a wide range of styles, including neo-classical composition, progressive/psychedelic rock, free-form improvisation, cosmic jazz, minimalist drone, ethereal synth-pop and outer-limits folk music.

O'Sullivan has collaborated with a number of artists including Stephen O'Malley (also a member of Æthenor), Alexander Tucker, Kristoffer Rygg[1] (Ulver), Jarboe[2] and David Tibet.

The debut album Furrier also features Jussi Lehtisalo from Finnish bands Circle and Pharaoh Overlord and David Smith from Guapo.

[9] Under the name Grumbling Fur Time Machine Orchestra, the duo has also released two collaborative recordings with Charlemagne Palestine in 2015 and 2017, both being limited vinyl editions.